第34卷第4期 2017年7月
土木工程与管理学报 Journal of Civil Engineering and Management
砂土注浆的颗粒流细观力学数值模拟
秦鹏飞
（郑州工业应用技术学院建筑工程学院，河南郑州450010）
Vol.34 No.4 July2017
摘要：灌浆工程隐蔽性较强，浆液扩散机理远不成熟。基于细观力学理论的PFC2D数值仿真试验技术，可以从细观角度研究灌浆过程中土颗粒的位移、变形运动及与浆液的耦合作用过程，为注浆机理研究开辟了一条新的途径。基于流固耦合原理的PFC2D颗粒流数值模拟程序，运用其内置FISHTANK函数库和FISH语言，分别定义流体域的流动方程和压力方程，对灌浆过程中浆液在地层中的扩散过程和形态进行了数值模拟计算。通过调节PFC命令流中的注浆压力、时间步长、水力传导系数等参数对浆液的注浆过程进行了模拟计算。模拟结果表明，灌浆过程中浆液与地基七的作用形式与灌浆压力大小密切相关，为达到理想的劈裂灌浆效果需要适当提高注浆压力，但过高注浆压力会对地层结构造成一定的破坏。对钻孔周围土体的应力状态进行了理论推导和分析，指出土体环向拉应力的增加导致钻孔周围产生劈裂缝，浆液由渗透作用方式向劈裂作用方式转变，数值模拟结果与理论推导结果相符。劈裂灌浆作用发生时，孔隙率和应变率均增加。流动性能差的稠浆适于压密灌浆和劈裂灌浆，流动性能好的稀浆则适于渗透性灌浆，而浆液的渗透性能对高压劈裂灌浆的作用效果影响不明显。
关键词：砂砾石土：注浆：颗粒流：数值模拟：注浆压力：注浆时间：渗透性质中图分类号：TU441+.1
文献标识码：A文章编号：2095-0985(2017)04-0030-09
Micromechanics Particle Flow Numerical Simulation on Sandy Soil Grouting
OINPeng-fei
( School of Architectural Engineering, Zhengzhou University of Industrial Technology,
Zhengzhou450010，China）
Abstract: As the strong invisibility of grouting, difusion mechanisms is still immature. PFC2D simulation test technology, which based
meso-mechanics, could study the displacement,
on
deformation of the particles and its coupling with the slurry, opening up a new route for grouting mechanism research. Based on the principle of fluid-structure coupling numerical simulation program, PFC2D particles flow, which uses its built-in FISHTANK function library and FISH language, and the flow equation and pressure equation of fluid domain have been defined, and the process of grouting slurry diffusion in the formation and shape are simulated and calculated. By adjusting the
parameter of step and perm in PFC'
command S
stream,grouting effects in different penetration
gravels were obtained. Numerical simulation indicates that action modes between serous fluid and ground soil are mutually affected by the grouting pressure, and ideal splitting injection effects could be obtained as the grouting pressure increase, while foundation structure will be destroyed as the pressure increase excessively. Stressed states around the drilling hole have been analyzed. Split seams around the drilling hole occur as the circumferential tension increase, and penetration modes of the slurry transits to splitting modes. Its results comply with the simulation. When split grouting method occurs porosity and strain increase. Thin slurry with superior flowing property is fit for penetration grouting, while thick slurry with inferior flowing property is fit for compaction grouting and split grouting Conductivity of the slurry affects the grouting little in high-pressure grouting
Key words: sandy soil; grouting; particle flow; numerical simulation; grouting pressure; grout time;
penetration
收稿日期：2016-05-12修回日期：2017-03-30
作者简介：秦鹏飞（1984-），男，河南鲁山人，博土，讲师，研究方向为地基处理（Email：qinpengfei@emails.bjut.edu.cn）基金项面：有数据业应用技术学院博土科研启动基金（201602001）